Climate Change and Dryland Agricultural Ecosystem Management
Climate Change and Dryland Agricultural Ecosystem Management
Climate Change and Dryland Agricultural Ecosystem Management
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transpiration water consumption in the windbreak in a "more in eastern regions <strong>and</strong> less in western<br />
regions, more in non-shading regions <strong>and</strong> less in shading regions" variation.<br />
Keywords: Oasis; Windbreak; Maize; Transpiration water consumption; Leaf area<br />
Fertilizer use efficiency <strong>and</strong> soil quality response to application of<br />
fertilizer <strong>and</strong> manure of newly built terraces on the semi-arid Loess<br />
Plateau of China<br />
Chang An Liu1, Shi Ling Lin, Rong He Zhang1, Li Min Zhou1, Feng Min Li1, *<br />
1 MOE Key Laboratory of Arid <strong>and</strong> Grassl<strong>and</strong> Ecology, School of Life Sciences, Lanzhou University, Lanzhou, Gansu<br />
Province 730000, PR China<br />
Abstract:Terracing is an effective method for developing agriculture, decreasing soil erosion <strong>and</strong><br />
increasing soil C in the region characterized by a hilly l<strong>and</strong>scape <strong>and</strong> limited soil resources. This paper<br />
determined the effects of fertilization on soil water content, fertilizer use efficiency <strong>and</strong> soil quality in<br />
newly built terraces on the semi-arid Loess Plateau of China. Pea, spring wheat, <strong>and</strong> potato grown on<br />
terraces established in May 2002 were subjected to four regimes involving chemical fertilizers <strong>and</strong>/or<br />
manure from August 2003 onwards: (1) control treatment with no fertilizer (CK), (2) nitrogen <strong>and</strong><br />
phosphorus (NP), (3) manure (M), <strong>and</strong> (4) manure, nitrogen <strong>and</strong> phosphorus (MNP). After 6 years,<br />
soil water in the upper 200 cm soil layer in MNP <strong>and</strong> M was kept in balance, while significant soil<br />
water depletion reached 140 cm soil layer in CK <strong>and</strong> NP compared to their values before sowing in<br />
2004. During the 6-year study, N agronomic efficiency was significantly higher in NP than in MNP<br />
<strong>and</strong> M; P agronomic efficiency was significantly higher in MNP than these in NP <strong>and</strong> M. Soil organic<br />
carbon (SOC) <strong>and</strong> soil total nitrogen (TN) <strong>and</strong> built up fast in manure treatments, <strong>and</strong> applying<br />
fertilizer alone can not be beneficial to increase SOC <strong>and</strong> TN in the short term, it is not the lack of P<br />
reserves in all treatments when the experiment was started. At the end of our 6-year experiment, the<br />
C/N ratios in MNP <strong>and</strong> M were significantly higher than those in other treatments. The ratio of soil<br />
available P to soil total P (AP/TP) <strong>and</strong> microbial carbon (MBC) content were significantly higher in<br />
MNP than in any other treatment from the second year. A significant positive correlation was found<br />
between MBC <strong>and</strong> MN (R = 0.85; P
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